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The optical near-field speckles and their first order statistics on the basis of the integral equations of electromagnetic field

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Science china(physics,Mechanics & Astronomy) 2004年第3期47卷 365-380页

作者： CHENG Chuanfu1, 2. SONG Hongsheng2. LIU Chunxiang2. REN Xiaorong2. ZHANG Ningyu3. TENG Shuyun1 & XU Zhizhan1 1. Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P. O. Box 800-2.1, Shanghai 2.1800, china 2. department of {2., shandong Normal University, jinan 2.0014. china 3. shandong Institute of {13. and engineering, jinan 2.0014. china Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghaichina department of physics{2. Normal University{3.china shandong Institute of architecture and {2.{3.china

From Helmholtz equation of the harmonic electromagnetic waves, the integral equations of the light field at the medium boundaries are obtained by use of the Green's theorem and are discretized into linear equation set with the values of the light field and its derivative as the unknowns. On solving the linear equation set, we realize the rigorous computations of the light fields at the boundaries. Then the intensities of the light waves scattered by the random self-affine fractal surfaces in the optical near-field are calculated, and the propagation characteristics, the evolutions of the contrast and the intensity probability density function of the near-field speckles are studied in detail. The near-field speckles are much different from the conventional speckles in the diffraction regions and in the imaging systems. There are obvious local fluctuations in the intensity distributions of the near-field speckles and such fluctuations disappear after propagating a distance of one wavelength from the medium surfaces. For the random surfaces with smaller lateral correlation lengths, the speckle contrasts approach the saturation values and the speckle fields approach Gaussian distribution within the near-field, while for the random surfaces with larger lateral correlation lengths, such evolutions become comparatively slow.

关键词： speckle, near-field optics, first order statistics, Green's function.

Recurrence spectra of He atoms in strong external fields

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Science china(physics,Mechanics & Astronomy) 2004年第4期47卷 477-484页

作者： LIN Shenglu1, LI Hongyun1, WANG Dehua2. ZHAO Wenli1 & GAO Feng1 1. department of physics, {2. Normal University, jinan 2.0014. china 2. department of mathematics and physics, {2. Institute of architecture and engineering, jinan 2.0014. china department of physics Shandong Normal University Jinan China department of mathematics and {2. Shandong Institute of Architecture and Engineering Jinan China

By employing a model potential including the electron exchange energy, we extend the semiclassical closed orbit theory to study the multielectron atoms. Using special region-splitting consistent and iterative method, we figure out the closed orbits in the corresponding classical system and calculate the recurrence spectra of triplet helium atoms in parallel electric and magnetic fields at scaled energy ε=?0.03.n≈40,n=0. The core-scattering effects have been taken into account, which lead to more peaks in the spectra. It has also been confirmed by means of the direct comparison between the spectral portrait in such a plot and those of hydrogen case. In order to compare the theoretic results with experiment, we investigate the closed orbits and recurrence spectra of helium atoms for the similar exchange potential but applied only by single electric field at scaled energy ε=?2.7 case. The spectra are in good agreement with the experimental observation. We conclude that our model is correct and it is necessary to consider the exchange effect for determining the photoabsorption spectra of multielectron atoms in strong external fields.

关键词： exchange potential, recurrence spectra, semiclassical closed orbit theory, core-scattering.

Morphology and electrical conductivity of PACS

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Journal of Environmental Sciences 2000年第3期12卷 319-324页

作者： GAO Bao\|yu\+1, LIU Zong\|gang\+2. YUE Qin\|yan\+3. ZHAO Hua\|zhang\+3.(1. department of Environmental engineering, {2. University, jinan 2.0100, china 2. Environmental Monitoring Station of Huaiyin, jinan 2.002., china 3. department of Environ 山东大学山东济南 2 50 1 0 0 山东济南市槐荫区环境监测山东济南 2 50 0 2 2

Polyaluminium chlorides with sulfate ion(PACS) were prepared by using AlCl 3.6H 2., Al(SO 4) 3.18H 2. and Na 2.O 3.as raw materials. The effects of basicity ( r ), Al 3. /SO 4 2. molar ratio and aging time on the morphology of PACS were observed by transmission electrical microscope. The influence of aging time on charge neutralization and coagulation effect of PACS was studied. The effects of basicity ( r ), Al 3. /SO 4 2. molar ratio and aging time on the electrical conductivity of PACS solution were also investigated. The experimental results show that the degree of polymerization of polyaluminium chloride(PAC) increases when SO 4 2. ion is added. The higher the basicity( r ) and the longer the aging time, the larger the size of polymer PACS. The ability of PACS neutralizing the charge on Kaolinite decreases with the increase of aging time. The electrical conductivity of PACS solution(the concentration of Al 3. ion is 0.18 mol/L) with different aging time is the function of the basicity and Al 3. /SO 4 2. molar ratios and has its maximum at r =0.5 and Al 3. /SO 4 2. =12.

关键词： coagulant PACS morphology transmission electron microscope electrical conductivity coagulation

Morita contexts on the Hopf algebroid

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Science china mathematics 2005年第7期48卷 958-971页

作者： YIN Yanmin School of Mathematical Sciences, Peking University, Beijing 100871, china department of {2., {3. Institute of architecture and engineering, jinan 2.0101, china School of Mathematical Sciences Peking University Beijing 100871 China department of mathematics Shandong Institute of Architecture and Engineering Jinan 250101 China

We generalize the Morita theory to the Hopf algebroid and give the characterization of the surjectivity of one of the Morita context maps.

关键词： comodule algebra, generalized smash product, Morita context.

Analysis on cohesive crack opening displacement considering the strain softening effect

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Science china(physics,Mechanics & Astronomy) 2006年第1期49卷 88-101页

作者： WANG Limin1, XU Shilang2.& ZHAO Xiqiang3.1. Mechanics department, shandong University of Technology, Zibo 2.5049, {2. 2. Civil engineering department, Dalian University of Technology, Dalian 11602., {2. 3. mathematics department, Ocean University of {2., Qingdao 2.6071, {2. Mechanics department Shandong University of Technology Zibo China Civil engineering department Dalian University of Technology Dalian China mathematics department Ocean University of China Qingdao China

In order to investigate the crack propagation in quasi-brittle materials like rock, ceramic and concrete, Hillerborg and his co-researchers abstracted the fracture process zone in front of a stress free crack in terms of a “fictitious crack zone”. On the fictitious crack zone, cohesive stresses distribute following a given softening relationship of stress vs. crack opening. Based on the polynomial or power series expression of cohesive crack opening displacement, the relationship of the cohesive stress vs. the crack opening displacement is established using elastic theory and integral equation, and some unknown physics variables are obtained using variation approach. The calculation results gained in this paper are close to the experimentally test ones.

关键词： cohesive crack, softening, dissipation work, variation approach.

The influence of laser pulse on the photoabsorption spectra of Li atom in strong external field

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Science china(physics,Mechanics & Astronomy) 2006年第2期49卷 178-186页

作者： WANG Dehua1 & LIN Shenglu2.1. School of physics and Electronic engineering, Yantai Normal University, Yantai 2.402., {2. 2. department of physics, shandong Normal University, jinan 2.0014. china School of physics and Electronic engineering Yantai Normal University Yantai China department of physics Shandong Normal University Jinan China

Using the time-dependent perturbation theory and the calculation formula of the single- and double-pulse absorption spectra of the atom in strong external fields, we calculate the single- and double-pulse absorption spectra of Li atom in strong magnetic field for different pulse widths. The results show that a pulse of some width can reduce the contribution of the short period closed orbits and eliminate the contribution of the long period orbits. Compared with the single-pulse absorption spectra, we found that for some phase differences, the double-pulse laser absorption spectra are strengthened; while for others, they are reduced. Therefore, we can use the pulse laser to control the oscillation of the absorption spectra and obtain the optimization object.

关键词： laser pulse closed orbit absorption spectra.

An investigation of hadronization mechanism at a Z^0 factory

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Science china(physics,Mechanics & Astronomy) 2010年第11期53卷 1998-2004页

作者： JIN Yi 1,SI ZongGuo 2.XIE QuBing 2.& YAO Tao 2.1 {3. of physics,University of {2.,{2. 2.002.,china 2.School of physics,shandong University,{2. 2.0100,china department of physics University of Jinan Jinan China School of physics Shandong University Jinan China

We briefly review the hadronization pictures adopted in the LUND String Fragmentation Model (LSFM),Webber Cluster Fragmentation Model (WCFM) and Quark Combination Model (QCM),*** of hadron multiplicity,baryon to meson ratios and baryon-antibaryon flavor correlations,especially those related to heavy hadrons at a Z 0 factory obtained by LSFM and QCM,are reported.

关键词： Z0 factory hadronization model baryon to meson ratio B correlation

Electronic structure and magnetism of R(Fe,Si)_(12. (R=Y,Nd)

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Science china(physics,Mechanics & Astronomy) 2006年第2期49卷 195-202页

作者： SUN Guang’ai1, CHEN Bo1, DU Honglin2. FAN Zhijian1, GAO Tao3.& QI Xinhua3.. Institute of Nuclear physics and Chemistry, china Academy of {2. physics, Mianyang 62.900, china 2. department of physics, Peking university, Beijing 100871, china 3. Institute of Atomic and Molecular physics, Sichuan University, Chengdu 610065, china Institute of Nuclear physics and Chemistry China Academy of Engineering Physics Mianyang China department of physics Peking university Beijing China Institute of Atomic and Molecular physics Sichuan University Chengdu China

The newly developed full-potential linearized augmented plane wave (LAPW) and local orbitals (lo) based on standard APW methods are briefly introduced, and the structure and magnetic properties of R(Fe, Si)12.compounds (R = Y, Nd) are calculated using the method. The distribution of Si at different sites is analyzed based on total energy of one crystal unit with structure having been optimized. The characters of magnetic mo-ments, total density of states (TDOS) and partial density of states (PDOS) for different crystal sites Si occupies are obtained and analyzed. The results show that the total mag-netic moments of RFe10Si2.(R = Y, Nd) are larger than those of RFe10M2.(M = Ti, V, Cr, Mn, Mo and W) and the hybridization mechanism is seen as follows. Si(8j) reduce the mag-netic moments of Fe at three sites, however, Si(8f) mainly reduce the magnetic moments of Fe(8i) and Fe(8j) atoms. The Curie temperature is markedly enhanced by the introduc-tion of Si atoms according to spin fluctuation of DOS at Fermi level.

关键词： (L)APW+lo method R(Fe Si)12.R = Y Nd) magnetic moment Density of state.

Large second-order optical nonlinearities of s-triazine derivatives: View from micro molecules to macro crystals

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Science china Chemistry 2005年第3期48卷 203-209页

作者： FANG Qi1, LEI Hong2. CUI Yuezhi3. HUANG Zhenli4, XUE Gang1 & YU Wentao1 1. State Key Laboratory of Crystal Materials, shandong University, jinan 2.0100, {2. 2. School of Information Science and engineering, shandong University, jinan 2.0100, {2. 3. department of Chemical engineering, Light Industry College of shandong, jinan 2.0100, {2. 4. Key Laboratory of Biomedical Photonics, Ministry of Education, Huazhong University of Science and Technology, Wuhan 43.074, {2. State Key Laboratory of Crystal Materials Shandong University Jinan China School of Information Science and engineering Shandong University Jinan China department of Chemical engineering Light Industry College of Shandong Jinan China Key Laboratory of Biomedical Photonics Ministry of Education Huazhong University of Science and Technology Wuhan China

Three s-triazine derivatives have been synthesized and their structures been de-termined. These are Compound I: 2.4-dimethyl-6-(p-N,N-dimethylaminostyryl)-s-triazine (abbre-viated to NMe-1), Compound II: 2.4-dimethyl-6-(p-N,N-diethylaminostyryl)-s-triazine (to NEt-1), and Compound III: 2.methyl-4,6-bis(p-N,N-dimethylaminostyryl)-s-triazine (NMe-2.. NMe-1 and NEt-1 molecules belong to the D-π-A type with a one-dimensional charge-transfer character. NMe-1 crystallizes to centrosymmetric P1 space group, while NEt-1 to non-centrosymmetric polar Cc space group with all of the molecular charge-transfer axes taking the same orientation. Under the irradiation of 1064 nm fundamental laser, NEt-1 powder crystals radiate a 2.order harmonic light with an intensity 46.8 times that of urea. The Λ typed NMe-2.molecule, which has a two-dimensional charge-transfer character, crystallizes to polar P2. space group. Its powder crystals exhibit a 2.order harmonic intensity 46.2.times that of urea. The quantum chemical cal-culations and tensor analyses have been carried out to reveal the dependence of the macro 2.order nonlinear optical (NLO) efficiency on the micro 2.order NLO coefficients (β) and on the crystalline packing styles.

关键词： s-triazine derivatives, synthesis, structure, SHG intensities of crystals, βvalues of molecules.